Galaxy S8 Plus is brighter at the top than the bottom. Is this normal?

It's especially noticeable on a screen that's a solid color like blue. Towards the top of the screen (the selfie camera end) the shade of blue will be noticeable brighter than the shade of blue towards the bottom of the screen.

It's no huge deal, a bit disappointing, but if it's not how it should be I have time to exchange it.